This invention relates to a device to control the lateral alignment of a continuous moving web of material and more particularly, to a device to control the lateral alignment of a continuous moving web of material by pivoting a guide roller at an angle to its normal position.
In the printing and stamping arts, among others, certain operations are performed on continuous webs of material which often move through machines at high speed. Accurate alignment of the web is usually required during such operations. However, the moving web often shifts from its proper lateral position on the rollers and guides supporting it, due to imperfections in the web or machinery. Displacement of the web from its true lateral position interferes with the operations being performed on the web and often results in spoilage or a defective product. Prior art devices designed to accurately adjust the lateral position of a continuous web are complicated in construction and entail considerable manufacturing expense. Thus, there is a need for a simple device which is easy to manufacture and can accurately adjust the lateral position of a moving web of material.
Accordingly, a primary object of my invention is to provide a new and improved device to control the lateral alignment of a continuous moving web of material.
Another object of my invention is to provide a device to control the lateral position of a continuous moving web of material by pivoting a guide roller at an angle to its normal position.
A further object of my invention is to provide a device capable of accurately controlling the lateral position of a web of material moving at a high speed.
Still another object of my invention is to provide a device to control the lateral position of a moving web of material which is simple in construction and easy to manufacture.
In the preferred embodiment of my invention; a guide roll is rotatably mounted on a support shaft which extends between two laterally-spaced arms. A continuous moving web of material passes over the guide roll in a 90.degree. wrap. A first pivot arm extends downward from a drive motor and is adapted to rotate in a vertical plane about a pivot point on the drive motor when the motor is actuated. The first pivot arm includes an aperture aligned with the axis of the support shaft and is adapted to receive an end of the support shaft in a loose fit, whereby the support shaft can be pivotally mounted in the aperture for limited pivotal movement. The second pivot arm is adapted to pivot in a vertical plane about a second pivot point offset 90.degree. from the first pivot point. A scanner assembly extends between the two pivot arms in close proximity to the guide roll and is designed to detect lateral misalignment of the moving web of material passing over the guide roll. When misalignment is detected, the scanner assembly activates the drive motor to pivot the guide roll from its position normal to the path of the moving web. The web is thus shifted back into proper lateral alignment.